Quite interesting. There are not actually that many Car Rental themes out there, at least not good ones.
I guess you have a few choices. Have a look at this theme and see what you think -
TanTum
When you read through the information on
TanTum you will see it also requires the
Car Rental System plugin. This plugin will probably work with a lot of themes, however they actually recommend TanTum, Avada and BeTheme, along with several others.
Therefore, this gives you quite a bit of scope.

Not sure if TanTum and plugin are on Babiato, but if needed, just ask.
Hope that is of some use!
TassieNZ